JPH0745672B2 - High concentration coal-water slurry regulator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for adjusting the properties of a high-concentration coal-water slurry, and more particularly to a high-concentration coal-water slurry stored in a storage tank in a boiler. The present invention relates to a device for adjusting properties suitable for combustion such as the above and supplying the same to other devices.

[Conventional technology]

Fuels used in combustion devices such as boilers include fluid fuels such as heavy oil and LNG, and solid fuels such as coal. A coal-water slurry prepared by suspending coal with an additive such as a surfactant and water to form a slurry has attracted attention as a boiler fuel because it facilitates handling during transportation and storage. This coal-water slurry, which is generally called CWM, has a high coal concentration of about 60% by weight or more when directly combusted, and its particle size is adjusted to about 70 to 90% through 200 mesh. Also in this case the CWM must be a pumpable and stable low viscosity liquid. The conditions for producing stable CWM with high slurry concentration, low viscosity and (1) increase the packing density of particles by adjusting a wide particle size distribution, and (2) add a dispersant. To form a water film on the surface of the particles and to charge them to disperse the particles to reduce the viscosity. CWM like this
In the case of continuously producing the, the method using a continuous wet pole mill is generally used.

FIG. 4 is a schematic system diagram of the CWM fuel system. In FIG. 4, coal 21 passes through a coal bunker 22 and a wet ball mill.
It is processed into CWM at 23. C manufactured by wet ball mill 23
The WM is stored in the storage tank 24 for a certain period of time, supplied to the service tank 25 by the pump 27, and burned in the boiler 26. The storage tank 24 is required to normally store for 30 to 60 days, and if it is long, for about 3 months. Also service tank
25 is long and needs to be stored for several days, and the properties of CWM are finally confirmed in the service tank 25 on the boiler side.

CWM combustion in a boiler is generally spray combustion, but when spraying CWM, the viscosity of CWM greatly affects the atomization characteristics.
As shown in FIG. 5, there is a characteristic that the average particle diameter of the spray increases as the viscosity of CWM increases. Especially CWM viscosity is 1500c
If it is p or more, the average particle diameter of the spray tends to increase remarkably, and the stability of combustion deteriorates. Furthermore, the pressure loss in the pipe also increases and the pump power also increases. Therefore, the viscosity of CWM is adjusted to 1000 cp ± 200 cp. However, since the storage period in the storage tank 24 is long, the CWM property is likely to change. Possible causes are alteration of additives, evaporation of water and changes in CWM temperature.

From the above, at present, the CW in the storage tank 24 is
M is sampled and the properties of CWM are measured and adjusted. FIG. 6 shows the method.

The storage tank 32 is filled with the slurry 31, and the stirrer 30 is provided on the upper portion. Stirrer blades at the bottom of the stirrer 30
33 is provided so that the slurry 31 in the storage tank 32 is forcibly stirred. A water tank 35 and a water pump 36 are installed above the storage tank 32 to supply a predetermined amount of water necessary for adjusting the viscosity of the slurry, and the agitator 30 forcibly agitates the slurry and the water.

[Problems to be solved by the invention]

In the system for adjusting the properties of CWM as described above, the rotation speed of the stirrer 30 is 60 in order to sufficiently stir the slurry and water.
It is necessary to have rpm to 120 rpm or more, which is in proportion to the size of the storage tank 32, and a large amount of stirring power is required.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to easily supply the properties of CWM stored in a tank, especially when adjusting the viscosity and then supplying the same to other devices such as a boiler without requiring a large power consumption. It is to provide a high-concentration CWM adjustment device capable of adjusting CWM.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention introduces a fluid such as water capable of adjusting the properties of CWM into the inlet side of a slurry pump installed on the outlet side of a storage tank for storing CWM, CWM has a predetermined viscosity and other characteristics.

[Action]

At the inlet side of the slurry pump installed on the outlet side of the storage tank that stores CWM, water, additives, or CW in the storage tank
When CWM having a viscosity different from that of M is introduced at a predetermined flow rate, the CWM flowing out of the slurry pump is adjusted to have a property according to the characteristics such as combustion. Therefore, it is not necessary to agitate the CWM of the storage tank with large power in order to adjust the properties of the slurry.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention. In Fig. 1, the valve 1 is installed in the slurry line from the slurry outlet 15 of the storage tank 1 that stores high-concentration CWM2.
0, a slurry pump 7 and a slurry flow meter 9 are sequentially installed, and the slurry pump 7 is driven by a motor 8. A water tank 3 is provided on the suction port side of the slurry pump 7.
The water line 14 from is connected. A water pump 4, a water flow meter 5 and a valve 6 are installed in the water line 14. In FIG. 1, 11 is an arithmetic unit and 12 is a controller.

In the high-concentration CWM adjusting device shown in FIG. 1, the CWM in the storage tank 1 is the valve 1 opened from the slurry outlet 15.
It is taken out of the system through 0 and the slurry pump 7.

The CWM on the slurry line after passing through the slurry pump 7 is introduced into the service tank 25 as shown in FIG. At this time, the flow rate of CWM on the slurry line is detected by the slurry flow meter 9, and the detection signal is input to the calculator 11.
Further, a detection signal of the water flow rate on the water line from the water flow meter 5 is input to the calculator 11. Each detection signal is processed by the arithmetic unit 11, and the processed signal is input to the controller 12. Then, the controller 12 controls the rotation speeds of the water pump 4 and the motor 8, and the water and the slurry introduced into the slurry pump 7 are adjusted to a predetermined amount.

Although water is supplied to the suction port side of the slurry pump in the above-described embodiments, a solution containing an additive may be used instead of water.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention. In FIG. 2, a storage tank 17 storing a slurry 16 having a viscosity different from that of the slurry 2 in the storage tank 1 is installed,
The slurry line from this storage tank 17 is the slurry pump 7.
It is connected to the suction port side. A slurry pump 18 and a slurry flow meter 19 are installed in this slurry line, and a flow rate detection signal from the slurry flow meter 19 is input to the controller 12. As in the case of FIG. 1, the slurry from the storage tank 17 and the storage tank are The slurries from 1 are controlled so that the slurries each have a predetermined amount.

In the embodiment shown in FIGS. 1 and 2, the slurry pump 7
The flow rate of the slurry on the slurry line and the flow rate of water or the CWM whose properties are to be adjusted and the adjustment CWM having different viscosities are detected, and water or the CWM for adjusting the total flow rate of the slurry is detected.
By controlling the injection amount of CWM, the property of CWM supplied to the apparatus such as the boiler can be adjusted. Also the first
In the embodiment shown in Figures and 2, the CW from the storage tank 1 is
It is also possible to adjust the property of CWM supplied to the boiler or the like by controlling the rotation speed of the motor 8 while keeping the injection amount of water or CWM for adjustment to M constant.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention. In FIG. 3, a slurry viscometer 20 is installed downstream of the slurry flow meter 9 provided on the slurry line from the slurry pump 7, and the viscosity of the CWM is continuously detected by the slurry viscometer 20. The detected value is processed by the arithmetic unit 11, and feedback control of the motor 8 attached to the water pump 4 and the slurry pump 7 is performed.

An online hydrometer is installed in place of the slurry viscometer 20 in the embodiment shown in FIG. 3, and this slurry hydrometer measures CW.
The viscosity of M may be continuously detected, and the detected value may be processed by the calculator 11 to perform feedback control of the motor 8 attached to the water pump 4 and the slurry pump 7.

In the embodiment shown in FIG. 3 and the embodiment in which the on-line hydrometer is provided, the characteristics of CWM can be reliably adjusted by the feedback control of the motors attached to the water pump 4 and the slurry pump 7.

In the present invention, by using a screw pump whose flow rate can be easily adjusted by positive displacement type rotational speed control in the slurry pump 7, a CWM to be adjusted and a fluid such as water capable of adjusting the properties of the CWM are screw pumps. Both can be sufficiently mixed by passing them once. As the screw pump, any one-shaft, two-shaft or three-shaft system can be used, but the clearance of these screw pumps is as small as 0.1 mm or less. Therefore, the structure is such that mixing of the CWM to be adjusted and a fluid such as water capable of adjusting the properties of the CWM is promoted.

〔The invention's effect〕

As described above, according to the present invention, the slurry pump already installed on the slurry line for supplying the CWM from the CWM storage tank to another device such as a boiler is used as it is, and the property of the high concentration CWM is obtained. Can be adjusted. Therefore, the properties of the CWM can be adjusted without requiring a great amount of power for stirring the high-concentration CWM in the storage tank.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing the first embodiment of the present invention, and FIG.
FIG. 4 is a schematic configuration diagram showing a second embodiment of the present invention, FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention, and FIG. 4 is a CWM.
Fig. 5 is a graph showing the relationship between the CWM viscosity and the average particle size of spray atomized by a burner.
FIG. 1 is a schematic configuration diagram of a conventional CWM adjusting device. 1 ... Storage tank, 2 ... Slurry, 3 ... Water tank, 4 ... Water pump, 5 ... Water flow meter, 7 ... Slurry pump, 8 ... Motor, 9 ... Slurry flow meter, 11 ... … Computer, 12 …… Controller, 17 …… Storage tank, 18 …… Slurry pump, 19 …… Slurry flow meter, 20 …… Slurry viscometer,

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Takezaki 3-36 Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi Ltd. Kure Research Institute (72) Toshinobu Shima 6-9 Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi Stock Company Kure Factory

Claims (5)

[Claims] 1. A high equipped with a slurry line for supplying the high-concentration coal-water slurry in the tank to another device through a slurry pump installed on the outlet side of a storage tank for storing the high-concentration coal-water slurry. Concentrated coal-water slurry handling device, a high-concentration coal characterized in that a line for introducing a fluid capable of adjusting the properties of the high-concentration coal-water slurry whose flow rate is controlled is provided on the suction port side of the slurry pump. -Water slurry adjuster 2. A high-concentration coal-water slurry adjusting device according to claim 1, wherein the fluid capable of adjusting the properties of the high-concentration coal-water slurry is water. 3. The high-concentration coal according to claim 1, wherein the fluid capable of adjusting the properties of the high-concentration coal-water slurry is a solution containing an additive used in CWM production. Water slurry adjuster. 4. The high-concentration coal-water slurry according to claim 1, wherein the fluid capable of adjusting the properties of the high-concentration coal-water slurry is a CWM having a viscosity different from the CWM to be adjusted. Adjusting device. 5. A slurry viscometer is installed on a slurry line on the outlet side of the slurry pump, and a CW from the slurry pump is installed.
The viscosity of M is continuously detected and the detected value is calculated,
The high-concentration coal-water slurry adjusting device according to claim (1), wherein the injection amount of the fluid capable of adjusting the properties of the high-concentration coal-water slurry to the CWM to be adjusted is controlled.